Yakult is prepared by adding glucose and glycine to skimmed milk, and heating the mixture at 90 to 95 °C for about 30 minutes. After letting it cool down to 45 °C, the mixture is inoculated with the lactobacillus and incubated for 6 to 7 days at 37 to 38 °C. After fermentation, water, sugar, gums and lactic acid are added.[2]

Health claims

In 2006, a panel appointed by the Netherlands Nutrition Centre to evaluate a marketing request by Yakult found there to be sufficient evidence to justify claims that drinking at least one bottle of Yakult per day might help improve bowel movements for people who tend to be constipated, and might help maintain a healthy population of gut flora.[3]

In 2010, an EFSA panel denied a request by the company to market Yakult as maintaining upper respiratory tract defenses against pathogens (in other words, protection against diseases like the common cold), finding the claim not supported by the evidence.[1]

In 2013, the UK Advertising Standards Authority disallowed an advertisement for Yakult in response to a complaint. It found that while there was sufficient evidence for the claim that “significant numbers of viable [Lactobacillus] survived transit to the gut [after consumption of Yakult]”, the advertisement had made claims of general health benefits without providing a specific, referenced claim, as required.[4]

Commercialisation

Yakult packs

Yakult was invented in the 1930s in Japan by Minoru Shirota and he helped found Yakult Honsha in order to commercialize it.[5] In some countries, including Japan and India, it is sold door-to-door. It was first sold in the Anglophone world in the 1990s, with Australia selling it first in 1994, the UK in 1996, and the US in 1999.[6]

In February 2018, it was reported that Danone planned to sell €1.5 billion of its Yakult investment, reducing its stake from 21% to 7%.[7][8] The plan was followed by a decline in Yakult’s share value.[9] Danone had first bought shares in Yakult in April 2000.[9] The sale was completed in March 2018.[10]

In September 2018, it was reported that the appearance of unlabelled Yakult bottles in the 2018 film To All the Boys I’ve Loved Before led to a rise in the drink’s sales that coincided with a 2.6% increase in share price following the film’s release on 17 August.[11][12]